Automated spacer frame fabrication and method

ABSTRACT

Method and Apparatus for fabricating a spacer frame for use in an insulating glass unit. One of a multiple number of possible spacer frame materials is chosen for the spacer frame. An elongated strip of the material is moved to a notching station where notches are formed at corner locations. The character of the notches is adjusted based on the selection of the metal strip material and more particularly to achieve bending of the material in an repeatable, straightforward manner. Downstream from the notching station the metal strip is bent into a channel shaped elongated frame member having side walls. Further downstream a leading strip of channel shaped material is severed or separated from succeeding material still passing through the notching and bending station.

CROSS REFERENCES TO RELATED APPLICATIONS

The following application is a non-provisional divisional patentapplication claiming priority under 35 USC sec 119 to co-pending U.S.non provisional patent application Ser. No. 14/198,706 filed Mar. 6,2014 entitled AUTOMATED SPACER FRAME FABRICATION AND METHOD, whichclaims priority under 35 USC sec 119(e) to U.S. Provisional applicationSer. No. 61/782,774 filed on Mar. 14, 2013 entitled AUTOMATED SPACERFRAME FABRICATION AND METHOD. The above two patent applications areincorporated herein by reference in their entireties and claims prioritytherefrom for all purposes.

TECHNICAL FIELD

The present disclosure relates to a method and apparatus for fabricatinga spacer frame for use in making a window or door.

BACKGROUND

Insulating glass units (IGUs) are used in windows and doors to reduceheat loss from building interiors during cold weather. IGUs aretypically formed by a spacer assembly sandwiched between glass lites. Aspacer assembly has a frame structure extending peripherally about theinsulating glass unit. A sealant material bonds the glass lites to theframe structure and a desiccant for absorbing atmospheric moisturewithin the unit, trapped between the lites. The margins or the glasslites are flush with or extend slightly outwardly from the spacerassembly. The sealant extends continuously about the frame structureperiphery and its opposite sides so that the space within the IGUs ishermetic.

U.S. Pat. No. 5,361,476 to Leopold discloses a method and apparatus formaking IGUs wherein a thin flat strip of sheet material is continuouslyformed into a channel shaped spacer frame having corner structures andend structures, the spacer thus formed is cut off, sealant and desiccantare applied and the assemblage is bent to form a spacer assembly.

U.S. Pat. No. 7,610,681 to Calcei et al, (hereinafter “the '681 Patent”)concerns spacer frame manufacturing equipment wherein a stock supplystation includes a number of rotatable sheet stock coils, an indexingmechanism for positioning one of the coils, and an uncoiling mechanism.Multiple other processing stations act on the elongated strip of sheetstock uncoiled from the stock supply station. The disclosure of the '681Patent is incorporated herein by reference.

U.S. Pat. No. 7,448,246 to Briese et al. (hereinafter “the 246 Patent”)concerns another spacer frame manufacturing system. As discussed in the'246 Patent, spacer frames depicted are initially formed as a continuousstraight channel constructed from a thin ribbon of stainless steelmaterial e.g., 304 stainless steel having a thickness of 0.006-0.010inches. As noted, other materials such as galvanized, tin plated steel,or aluminum can be used to construct the spacer frame. The disclosure ofthe '246 Patent to Briese et al is also incorporated herein byreference. Typical thickness for these other materials range from 0.006to 0.025 inches in thickness.

U.S. pending patent application Ser. No. 13/364,848 published as US2012/0011722 A1 discloses a system for forming spacer frames from one ofa multiple number of possible spacer frame materials. The contents ofthis pending patent application are incorporated by reference in theirentirety for all purposes.

SUMMARY

A disclosed system and method fabricates window components such as aspacer frame used in making an insulating glass unit. One of a multiplenumber of possible materials is chosen from which to make the windowcomponent. An elongated strip of the chosen material is moved to anotching station where notches are formed at corner locations. Thecharacter of the notches is adjusted based on the selection of the stripmaterial and more particularly to achieve bending of the material at thecorner locations in an repeatable, attractive manner. Downstream fromthe notching station in the example of a spacer frame, the strip is bentinto a channel shaped elongated frame member having side walls. Furtherdownstream a leading portion of channel shaped material that forms aforwardmost spacer frame is severed or separated from succeedingmaterial still passing through the notching and bending stations.

One system produces different width spacer frames by using differentwidth strip material. The corner locations are formed before the stripis roll formed into a channel shape by a die and anvil pairappropriately positioned (by appropriate side movement with respect to astrip path of travel) on opposite sides of the strip. A punch moves thedie into contact with the strip to remove part of the strip and todeform in a controlled way a part of the strip near the removed portion.

These and other features of the disclosure will become more fullyunderstood by a review of a description of an exemplary system whenreviewed in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing and other features and advantages of the presentdisclosure will become apparent to one skilled in the art to which thepresent disclosure relates upon consideration of the followingdescription of the disclosure with reference to the accompanyingdrawings, wherein like reference numerals refer to like parts unlessdescribed otherwise throughout the drawings and in which:

FIG. 1 is a perspective view of an insulating glass unit;

FIG. 2 is section view as seen from the plane 2-2 of FIG. 1;

FIGS. 3 and 4 are top and side views of a spacer frame (prior to beingfolded into a closed-multi-sided frame) that forms part of the FIG. 1insulating glass unit;

FIG. 5 is a schematic depiction of a production line for use with theinvention;

FIG. 6 is a perspective view of a stock supply station;

FIG. 7 is an elevation view of a corner stamping unit that forms part ofa punch station;

FIG. 8 is a perspective view of a punching station;

FIG. 9 is side elevation view of a corner stamping unit having spacerelements that position a strip in relation to a die as the strip movesinto position for stamping;

FIG. 10 is a plan view of a portion of an elongated metal strip for usein forming a spacer frame;

FIGS. 11, 11A, 12, and 12A are perspective views of a die set includinga punching die and a deformation die;

FIG. 13 is a perspective view of a crimping finger;

FIG. 14 is a perspective view of a section of strip stock after it hasbeen passed through a roll former;

FIG. 15 is a section view of a punch station having a capability formoving a set of dies back and forth to accommodate different widthstock;

FIGS. 16 and 16A are a pneumatic schematics showing solenoid valves thatselectively supply air to air actuated cylinders at the punch station;

FIG. 17 is a schematic showing two air actuated cylinders for formingcorners that have a flow control valve that limits a rate of airescaping a pressured chamber of the cylinder;

FIG. 18 is a side elevation view showing support structure for amoveable die and anvil;

FIG. 19 is a perspective view of a stop actuator;

FIGS. 20 and 21 are perspective views of a die support and an anvilsupport depicting placement of stop assemblies for controlling movementof the die support;

FIGS. 22, 23, and 24 are front, side and rear elevation views of a diesupport and an anvil support depicting placement of stop assemblies forcontrolling movement of the die support during stamping of a cornerlocation on a strip;

FIG. 25 is a top plan view of a die support;

FIG. 26 is a bottom plan view of an anvil support;

FIG. 27 is a perspective view of a stop assembly;

FIG. 28 is an exploded perspective view of the stop assembly of FIG. 27;

FIGS. 29 and 30 are front and side views of the stop assembly of FIG.27;

FIG. 31 is a view as seen from the plane defined by the line 31-31 inFIG. 30;

FIG. 32 is a view as seen from the plane defined by the line 32-32 inFIG. 30;

FIG. 33 is a perspective view showing a passageway for routing fluidthrough a stop assembly support;

FIG. 34 is a view as seen from the plane defined by the line 34-34 inFIG. 30;

FIG. 35 is a view as seen from the plane defined by the line 35-35 inFIG. 30;

FIG. 36 is a view as seen from the plane defined by the line 36-36 inFIG. 30;

FIG. 37 is a perspective view of a stop actuator;

FIG. 38 is a view as seen from the plane defined by the line 38-38 inFIG. 30;

FIG. 39 is a section perspective of a stop assembly;

FIG. 40 is a view as seen from the plane defined by the line 40-40 inFIG. 30; and

FIG. 41 is a schematic of a flow control used in re-orienting the stopassembly to position a controlled one of the stops of a stop assembly.

DETAILED DESCRIPTION

Referring now to the figures generally wherein like numbered featuresshown therein refer to like elements throughout unless otherwise noted.The present disclosure provides both a method and apparatus forfabricating a spacer frame for use in making a window or door. Morespecifically, the drawing Figures and specification disclose a methodand apparatus for producing elongated spacer frames used in makinginsulating glass units. The method and apparatus are embodied in aproduction line that forms material into spacer frames for completingthe construction of insulating glass units. While an exemplary systemfabricates metal frames, the disclosure can be used with plastic framematerial extruded into elongated sections having corner notches.

IGUs

An insulating glass unit (IGU) 10 is illustrated in FIG. 1. The IGU 10includes a spacer assembly 12 sandwiched between glass sheets, or lites,14 (FIG. 2). The assembly 12 comprises a frame structure 16 and sealantmaterial 18 for hermetically joining the frame to the lites to form aclosed space 20 within the unit 10. The unit 10 is illustrated in FIG. 1as in condition for final assembly into a window or door frame, notillustrated, for ultimate installation in a building. The unit 10illustrated in FIG. 1 includes muntin bars that provide the appearanceof individual window panes.

The assembly 12 maintains the lites 14 spaced apart from each other toproduce a hermetic insulating space 20 between them. The frame 16 andthe sealant body 18 co-act to provide a structure which maintains thelites 14 properly assembled with the space 20 sealed from atmosphericmoisture over long time periods during which the unit 10 is subjected tofrequent significant thermal stresses. A desiccant 22 removes watervapor from air, or other volatiles, entrapped in the space 20 duringconstruction of the unit 10.

The sealant 18 both structurally adheres the lites 14 to the spacerassembly 12 and hermetically closes the space 20 against infiltration ofairborne water vapor from the atmosphere surrounding the unit 10. Onesuitable sealant 18 is formed from a “hot melt” material which isattached to the frame 16 sides and outer periphery to form a U-shapedcross section.

The frame 16 extends about the unit's periphery to provide astructurally strong, stable spacer 12 for maintaining the lites 14aligned and spaced while minimizing heat conduction between the litesvia the frame. The preferred frame 16 comprises a plurality of spacerframe segments, or members, 30 a-d connected to form a planar, polygonalframe shape, element juncture forming frame corner structures 32 a-d,and connecting structure 34 (FIG. 3) for joining opposite frame elementends to complete the closed frame shape.

The preferred frame 16 is elongated and has a channel shaped crosssection defining a peripheral wall 40 and first and second lateral walls42, 44. See FIG. 2. The peripheral wall 40 extends continuously aboutthe unit 10 except where the connecting structure 34 joins the two framemember ends. The lateral walls 40, 42 extend inwardly from theperipheral wall 40 in a direction parallel to the planes of the lites 14and the frame 16. The illustrated frame 16 has stiffening flanges 46formed along the inwardly projecting lateral wall edges. The lateralwalls 42, 44 add rigidity to the frame member 30 so it resists flexureand bending in a direction transverse to its longitudinal extent. Theflanges 46 stiffen the walls 42, 44 so they resist bending and flexuretransverse to their longitudinal extents.

The frame 16 is initially formed as a continuous straight channelconstructed from a thin ribbon of material. As described more fullybelow, the corner structures 32 a-32 d are made to facilitate bendingthe frame channel to the final, polygonal frame configuration in theunit 10 while assuring an effective vapor seal at the frame corners. Asealant is applied and adhered to the channel before the corners arebent. The corner structures initially comprise notches 50 and weakenedzones 52 formed in the walls 42, 44 at frame corner locations. See FIG.4. The notches 50 extend into the walls 42, 44 from the respectivelateral wall edges. The lateral walls 42, 44 extend continuously alongthe frame 16 from one end to the other. The walls 42, 44 are weakened atthe corner locations because the notches reduce the amount of lateralwall material and eliminate the stiffening flanges 46 and because thewalls are stamped or coined to weaken them at the corners.

At the same time the notches 50 are formed, the weakened zones 52 areformed. These weakened zones 52 are cut into the strip, but not all theway through. The connecting structure 34 secures the opposite frame ends62, 64 together when the frame 16 has been bent to its finalconfiguration. The illustrated connecting structure comprises aconnecting tongue structure 66 continuous with and projecting from theframe structure end 62 and a tongue receiving structure 70 at the otherframe end 64. The preferred tongue and tongue receiving structures 66,70 are constructed and sized relative to each other to form a telescopicjoint. When assembled, the telescopic joint maintains the frame 16 inits final polygonal configuration prior to assembly of the unit 10.

The Production Line 100

As indicated previously the spacer assemblies 12 are elongated windowcomponents that may be fabricated by using the method and apparatus ofthe present invention. Elongated window components are formed at highrates of production. The operation by which elongated window componentsare fashioned is schematically illustrated in FIG. 5 as a productionline 100 through which a thin, relatively narrow ribbon of sheet metalstock is fed endwise from a coil into one end of the assembly line andsubstantially completed elongated window components emerge from theother end of the line 100.

The line 100 comprises a stock supply station 102, a punching station104, a roll forming station 106, a crimper station 108, and a severingstation 110 where partially formed spacer w members are separated fromthe leading end of the stock. At a desiccant application station 112desiccant is applied to an interior region of the spacer frame member.At an extrusion station 114 sealant is applied to the yet to be foldedframe member. A scheduler/motion controller unit 120 interacts with thestations and loop feed sensors to govern the spacer stock size, spacerassembly size, the stock feeding speeds in the line, and otherparameters involved in production. At an assembly station 116, the glasslites are affixed to the frame and sent to an oven for curing.

As described more fully in the Calcei et al. patent, elongated coils130-139 (FIG. 6) are supported to a carriage 140 for back and forthmovement in the direction of the double ended arrow 142. One of themultiple coils is moved by the controller 120 to an uncoiling positionfor delivering a selected strip of sheet stock material to thedownstream stations depicted in FIG. 5.

The scheduler/motion controller unit 120 interacts with the stations andloop feed sensors to govern the spacer stock size, spacer assembly size,the stock feeding speeds in the line, and other parameters involved inproduction. A preferred controller unit 120 is commercially availablefrom Delta Tau, 21314 Lassen St, Chatsworth, Calif. 91311 as part numberUMAC.

The Punching Station 104

The punching station 104 accepts the stock S from a properly positionedcoil at the stock supply station and performs a series of stampingoperations on the stock as the stock S passes through the punchingstation. The punching station 104 comprises a supporting framework 238(FIG. 11) fixed to the factory floor. A stock driving system 140 movesthe stock through the station until the stock is grasped by a downstreamdrive system 145 (FIG. 11) described in more detail in the Calcei et al.'681 Patent. Stamping units 144, 146, 148, 150, 152, 154 spaced alongthe station 104 in the direction of stock movement perform individualstamping operations on the stock S.

The illustrated stock driving system 140 includes a pair of rollers 156,158 secured to the framework at an entrance to the punching station 104.The rollers 156, 158 are selectively moveable between a disengagedposition in which the drive rollers are spaced apart and an engagedposition in which the drive rollers engage an end portion of the strip Sat the entrance of the punching station 104. The rollers 156, 158selectively feed the sheet stock into the punching station 104.

In the illustrated embodiment, a drive roller 156 is selectively drivenby a motor coupled to a drive shaft 162 that is controlled by thecontroller 120. An idle roller 158 is pivotally connected to its supportframework. In the illustrated embodiment, the roller 158 is an idlerroller that presses the sheet stock S against the roller 156 when thedrive roller 156 is in the engaged position. The motor is controlled tofeed the sheet stock through the station 104. In the illustratedembodiment, a sensor is positioned along the path of travel near thestamping station and creates an output for verifying that stock S isbeing fed.

The controller moves the pair of rollers 156, 158 to the disengaged,spaced apart position and indexes or moves an appropriate or selectedsheet stock coil from the plurality of coils 130-439. At the uncoilingposition, a feed mechanism positions the sheet stock end portion betweenthe pair of rollers 156, 158. The controller 120 moves the pair ofrollers 156, 158 to the engagement position to engage the coil endportion, and rotates the drive roller to feed the sheet stock into thepunching station. In one embodiment, the stock driving system 140 isalso used to withdraw stock from the stamping station 104 when stripstock of a different thickness, width or material is to fabricated intospacer frames.

In the disclosed system, a stock driving system 145 on an output side ofthe punching station 104 engages the stock provided by the stock drivingsystem 140. The stock driving system 140 then disengages. The subsequentdownstream drive system 145 has rolls that define a nip for securelygripping the stock and pulling it through the station 104 past a numberof stamping units 144, 146, 148, 148′, 150, 150′, 152, 154. Thedownstream drive system includes an electric servomotor to start andstop with precision. Accordingly, stock passes through the station 104at precisely controlled speeds and stops precisely at predeterminedlocations, all depending on signals from the controller 120.

Each stamping unit 144, 146, 148, 150, 152, 154 comprises a die assemblyand a die actuator assembly, or ram assembly. Each die assemblycomprises a die set having a lower die, or anvil, beneath the stocktravel path and an upper die, or hammer, above the travel path. Thestock passes between the dies as it moves through the station 104. Eachhammer is coupled to its respective ram assembly. Each ram assemblyforces its associated dies together with the stock between them toperform a particular stamping operation on the stock.

Each ram assembly is securely mounted atop the framework 238 andconnected to a fluid supply source 542 (FIG. 22) of high pressureoperating air via suitable conduits. Each ram assembly is operated fromthe controller 120, which outputs a control signal to a suitable orconventional ram controlling valve arrangement when the stock has beenpositioned appropriately for stamping.

The stamping unit 152 punches the connector holes 82, 84 (FIG. 3) in thestock at the leading and trailing end locations of each frame member 16.When included, a passage 87 is also punched in the stock by the unit152. In the illustrated embodiment, the die set anvil for punching theholes 82, 84 defines a pair of cylindrical openings disposed on thestock centerline a precise distance apart along the stock path oftravel. The corresponding hammer is formed in part by correspondingcylindrical punches, each aligned with a respective anvil opening anddimensioned to just fit within the aligned opening. The stamping unitram is actuated to drive the punches downwardly through the stock andinto their respective receiving openings. The stock is fed into thestamping unit 152 by the downstream driving system and stopped withpredetermined stock locations precisely aligned with the stamping unit152. The punches are actuated by the ram so that the connector holes 82,84 are punched on the stock midline, or longitudinal axis. When thepunches are withdrawn, the stock feed resumes.

The stamping unit 148 forms the frame corner structures 32 b-d but notthe corner structure 32 a adjacent the frame tongue 66. The stampingunit 148 includes a die assembly (FIG. 7) operated by a ram assembly.The die assembly 280 punches material from respective stock edges toform the corner notches 50. The die assembly 280 also stamps the stockat the corner locations to define the weakened zones 52, whichfacilitate the folding of the spacer frame member at the cornerlocations. The ram assembly preferably comprises a pair of air actuateddrive cylinders 290, 292 (FIG. 17) connected to an upper die drive plate400. Each weakened zone 52 is illustrated as formed by a score line(more than one score line may be included) radiating from corner bendline location on the stock toward the adjacent stock edge formed by thecorner notch 50. The score line is formed on the stock strip S by asharp edged ridge 457 disposed on a scoring tool 458 (FIG. 12, 12A) whencontact occurs on the strip S between the scoring tool 458 and a flatsurface or flat anvil. A face 459 of the tool 458 that engages the stripstock has a wedge shaped lip or ridge 457 spaced from two triangularelevated lands 461, 463. The elevated shaped lands 461, 463 bias theweakening zones 52 inward along the lateral walls 42, 44 at the notches50. In the illustrated embodiment, the frame members 16 produced by theproduction line 100 have common side wall depths even though the framewidth varies.

The stamping unit 150 configures the leading and trailing ends 62, 64 ofeach spacer frame member. The unit 150 comprises a die assembly operatedby a ram assembly. The die assembly is configured to punch out theprofile of the frame member leading end 62 as well as the profile of theadjoining frame member trailing end 64 with a single stroke. The leadingframe end 62 is formed by the tongue 66 and the associated cornerstructure 32 a. A trailing frame end 64 associated with the precedingframe member is immediately adjacent the tongue 66 and remains connectedto the tongue 66 when the stock passes from the unit 150. The ramassembly comprises a pair of rams each connected to a hammer.

The corner structure 32 a is generally similar to the corner structures32 b-d except the notches 50 associated with the corner 32 a differ dueto their juncture with the tongue 66. The die assembly thereforecomprises a score line forming a ridge like the die set forming theremaining frame corners 32 b-d.

The stamping unit 146 forms muntin bar clip mounting notches in thestock. The muntin bar mounting structures include small rectangularnotches. The unit 146 comprises a ram assembly coupled to the notchingdie assembly. An anvil and hammer of the notching die assembly areconfigured to punch a pair of small square corner notches on each edgeof the stock. Accordingly the ram assembly comprises a single ram whichis sufficient to power this stamping operation. A single stroke of theram actuates the die set to form the opposed notches simultaneously andin alignment with each other along the opposite stock edges.

Each time a new strip passes through the stamping station 104, a scrappiece of stock is formed that is followed by a connected first spacerframe defining length of stock in a given series of multiple spacerframes. In one embodiment, the scrap piece is defined by the punchingstation 104 whenever a different coil is indexed to the uncoilingstation and fed into the punching station 104. The stamping unit 144configures a leading edge of the scrap piece and trailing end 64 of thelast spacer frame member in a series of spacer frame members formed froma particular coil from which the strip unwinds. The trailing edge of thescrap unit is formed by the stamping unit 150 when the leading edge ofthe first spacer in the next series of spacers formed from thisparticular sheet stock coil is stamped. The unit 144 comprises a dieassembly operated by a ram assembly. The die assembly is configured topunch out the profile of the scrap piece leading end as well as theprofile of the end 64 of the last frame member in the series of spacerframe members with a single stroke. The rain assembly comprises a pairof rams each connected to a hammer.

At the end of a series of spacer frame members, the stamping unit 144forms the trailing end of the last spacer frame member in the series andthe leading end of the scrap piece. The stock is then indexed to astamping unit 154 where the connection between the end of the lastspacer frame member and the leading end of the scrap piece is severed.The unit 154 comprises a die assembly operated by a ram assembly. Thedie assembly punches the material that spans the respective stock edgesto sever the stock. The ram assembly preferably comprises a ramconnected to the upper die.

A sensor detects the end of the last spacer frame in a series of spacerframe members. Upon detection of the severed end of the last spacerframe, the controller 120 causes the stock feed mechanism 140 to movethe rollers 156, 158 to the engaged position. The controller thenactuates the motor to cause the drive roller to pull or retract thestock S out of the stamping station 104 and position the stock end atthe entrance to the punching station. The stock that forms the lastspacer frame member in the series is driven out of the machine by thedownstream stock driving mechanism. The controller then moves the stockfeed mechanism 140 to the disengaged position to release the stock end.The stock end remains secured by a clamping mechanism (not shown). Thecontroller 120 may then index the next selected coil to the uncoilingposition and place the end of this next selected strip between therollers 156, 158. The controller 120 then controls the stock feedmechanism to start the next series of spacer frame units.

In order to accommodate wider or narrower stock passing through thestation 104, the die assembly is split into two parts. In oneembodiment, one side of each die assembly is fixed and the opposite sideof each split die assembly is adjustably movable toward and away fromthe corresponding fixed die assembly to allow different width spacerframes to be punched. Also, each anvil is split into two parts and eachhammer is likewise split.

FIGS. 8 and 15 illustrate an example embodiment having a fixed sidearray of dies wherein an opposite side of the strip S path of travelincludes moveable die sets. The moveable opposed hammer and anvil partsare linked by vertically extending guide rods 302. The guide rods 302are fixed in the hammer parts and slidably extend through bushings inthe opposed anvil parts. The guide rods 302 both guide the hammers intoengagement with their respective anvils and link the hammers andrespective anvils so that all the hammers and anvils are adjustedlaterally together.

Referring to FIG. 15, the moveable hammer and anvil parts of each dieassembly that make up the punching station 104 are movable horizontallytowards and away (see Arrows X in FIG. 15) from the fixed hammer andanvil parts by an actuating system 304 to desired adjusted positions forworking on stock of different widths. The actuating system 304 firmlyfixes the die assembly parts at their horizontally adjusted locationsfor further frame production. The anvil parts of each die assembly arerespectively supported in ways or guides attached to driving members319, 320, 321, 322, 323, 325 attached to a stamping unit frame 238. Thehammer parts of each die assembly are also each supported in ways orguides, which are coupled to a respective die actuator, or ram. Theguides extend transversely to the travel path P of the stock strip S andthe actuating system 304 shifts the hammer parts and the anvil partssimultaneously along the respective ways between adjusted positions.

The illustrated actuating system is controlled by the controller 120 toautomatically adjust the punching station 104 for the stock widthprovided at the entrance of the station. The width of the stock providedto the station 104 may be detected and the controller automaticallyadjusts the station 104 to accommodate the detected width. Theillustrated actuating system 304 provides positive and accurate moveabledie assembly section placement relative to the stock path of travel. Thesystem 304 comprises a plurality of drivescrews 316, a drivetransmission 318 coupled to the drivescrews, and die assembly drivingmembers 319, 320, 321, 322, 323, 325 driven by the drivescrews 316 andrigidly linking the drivescrews to the anvil parts. The drivetransmission 318 is attached to a die spacer 465 (described below) whichrigidly attaches to an anvil support.

The drivescrews 316 are disposed on parallel axes and mounted in bearingassemblies connected to lateral side frame members. Each drivescrew isthreaded into its respective die assembly driving member 319, 320, 321,322, 323, 325. Thus when the drivescrews rotate in one direction thedriving members 319, 320, 321, 322, 323, 325 force their associated diesections (hammer and anvil) to shift horizontally away from the fixeddie sections. Drivescrew rotation in the other direction shifts the diesections toward the fixed die sections. The threads on the drivescrews316 are precisely cut so that the extent of lateral die section movementis precisely related to the angular displacement of the drivescrewscreating the movement.

The hammer sections of the die assemblies are adjustably moved by theanvil sections. The guide rods 302 extending between confronting anviland hammer die sections are structurally strong and stiff and serve toshift the hammer sections of the die assemblies horizontally with theanvil sections. The hammer sections are relatively easily moved alongthe upper platen guides or ways.

Once the strip S leaves the punching station 104, it enters a rollforming station 106 wherein a series of rolls contact the strip and bendit into a U-shaped channel or form 312 shown in FIG. 21. Roll formersfor accepting elongated strip and converning them into channel shapedelongated metal U shaped channels are know in the art and one example ofsuch a roll former is commercially available from GED IntegratedSolutions Inc., assignee of the present disclosure.

Controlled Corner Formation

As mentioned previously the ram assembly that forms part of the stampingunit 148 preferably comprises a pair of rams supported by the frameworkmost preferably implemented using two air actuated drive cylinders 290,292 (FIG. 17) commercially available from Festo Corp, under thedesignation or model number 13049375 or 13005438. An upper die assemblyincludes a drive plate 400 for at least two dies which move up and down(+/−⅜″) along the y axis seen in the elevation view of FIG. 7. Downwardmovement of the drive plate 400 attached to the two dies is limited byone or more ram limiting stop assemblies 410 having a contact region orsurface whose position with respect to a die support is adjusteddepending on the material of the strip S passing through the station104.

In an exemplary embodiment, the stamping unit has a first moveable diesupport 420 that supports one die for deforming one side of the strip Sand a second moveable die support 422 that supports a second die fordeforming an opposite side of the strip. These two die supports arecoupled to the drive plate 400 for up and down movement with the driveplate in response to controlled actuation of the two air actuated drives290, 292. In the embodiment of FIGS. 7 and 9, both dies can be shifted(+/− approximately ¾ inch in the X direction, see FIG. 7) to the side toaccommodate different width strips S. When the two air actuated drivecylinders extend their pistons, the plate 400 is driven downward (−y)along with the attached die supports 420, 422 to bring the first andsecond dies into engagement with the strip. Bottom surfaces 424, 426 ofthe die supports 420, 422 engage the contact surfaces of the stopassemblies 410 as a means of limiting movement of the dies and hencecontrolling the deformation of the strip S by those dies.

The stamping unit 148 has first and second moveable anvil supports 430,432 each supporting a stripping element 440 that the die passes throughto come in contact with the strip S and a die contact or backing element442. A region between the stripping element and the die contact element442 defines a slot 444 which accomodates movement of the strip S throughthe punching station 104. Guide rollers (not shown) route the stripstock S (along the z direction as defined in FIG. 7) into the region ofthe die with great accuracy (within 5 thousands of an inch) so that thestrip just passes through the slot 440 without binding. The die contactelement 442 has a flat upwardly facing surface 442 a which the die andparticular the die ridge 459 (FIG. 12A) engages to deform the metalstrip S when the metal strip is impacted by downward movement of thedie.

A representative die 450 is removably connect to respective die supports451, 453 and is depicted in FIGS. 11, 11A, 12, and 12A. The die 450includes a notching portion 452 for removing metal from the strip S anda deforming portion 454 for deforming a portion of the metal of thestrip near the removed metal to facilitate formation of a corner.

In the illustrated example embodiment of FIG. 7, there are stopassemblies 410 on opposite sides of the strip S path of travel havingupper facing, generally planar adjustable stop surfaces (described indetail below) which are contacted by the bottom surfaces 424, 426 of thedie supports 420, 422 for limiting transfer of energy from the dies tothe strip and thereby control deformation of the strip.

Die/Anvil Positioning

As mentioned above, the first and second anvil supports 430, 432 arecoupled to their respective die supports 420, 422 by connecting guides302. This arrangement is further depicted in FIG. 21 and FIGS. 23-29.The connecting guide 302 is securely attached to an associated diesupport 420 and extends through bushings 303 supported by the anvilsupport. This construction allows up and down movement of the diesupports with respect to their associated anvil supports. These guidessupport and define the movement of the ram assembly with respect to thestrip stock and are located in prescribed positions reducing frictionand misalignment. Additionally as the anvil support is being translatedback and forth to accept different width strip stock the guide 302transmits a force to move the die support 420 relative the drive plate400 in unison with the anvil support.

Unlike the example embodiment of FIG. 15, wherein only one set of anviland dies are moved by the control 120, the embodiment shown in FIG. 15is adjusted by manual rotation of a drive screw 470 that is rotated by ahand crank 471 in one sense or the other to either widen or narrow thegap between the dies and respective anvils. The exemplary drive screw470 is an acme screw having two halves 470 a, 470 b of different threaddirection connected together by a coupling 472. Each half of the drivescrew engages a corresponding drive nut so that for example the drivescrew half 470 a engages a drive nut 473 a and the drive screw half 470b engages a drive nut 473 b. In another embodiment not shown, the handcrank is replaced by a motor.

Two movable mounts 474, 475 are attached to the drive nuts 473 a, 473 bso that as rotation of the screw halves moves the drive nuts, the mounts474, 475 move as well. Due to the reverse threads used in the screwhalves, the mounts 474, 475 move in opposite directions along the x axisas that axis is defined in FIG. 15. As the mount 474 moves in thepositive x direction for example, the mount 475 moves in the negative xdirection.

Threaded connectors 476, 477 attach removable stops 478, 479 to themounts 474, 475 so that the stops move back and forth with the mounts asthe screw halves are rotated. As seen also in FIG. 9, an adjustablespacer 465 is trapped or wedged between the removable stops 478, 479 andthe anvil supports 430, 432. These spacers 465 have two surfaces 480,481 (FIG. 26) trapped between generally planar surface of a removablestop and an anvil support.

As seen in FIG. 9, a first pair of die and anvil assemblies are moveablysupported by an elongated support 494 which extends to an opposite sideof the strip stock path of travel where a second pair of die and anvilassemblies are moveably coupled to said elongated support. FIG. 21illustrations stationary guides or ways 309, 311, 313, 315 that guidethe die support 420 and the anvil support 430 for back and forthmovement in response to user adjustment of the crank. As seen in thefigure, the anvil support 430 has two elongated flanges 431, 433 thatextend into the ways 309, 315 and slide back and forth in those ways.

Stop Assembly 410

Exemplary stop assemblies 410 (FIG. 27) have two generally cylindricalstops 810, 812 made of hardened tool steel attached to a rotatable stopbody 814. The two stops have different thickness dimensions (asindicated in the y direction of FIG. 27) and are supported by the stopbody 814 for rotation about an axis of rotation 816 so that one or theother (but not both) of the stops 810, 812 is positioned for contactingthe bottom surface 424 of the die support 420 as the die support isdriven by the punch. Details of the construction of the stops aredepicted in the exploded perspective of FIG. 28. An exemplary removableportion 820 of the stop 810 is made of hardened tool steel and acentrally located recess 822 fits over an upwardly extending stud 824 ofthe rotatable stop body 814. A removable portion 821 of the stop 812 issimilarly positioned on a stud 825. Four cylindrical magnets 830 attractthe removable stop portion 820 and fit into recesses 832 of therotatable stop body 814 and have top surfaces flush with a top surface834 of the rotatable stop body 814.

In the exemplary embodiment, the thickness or height of the two stops810, 812 are different and more specifically varies over a range toadjust downward movement of the die by as much as 0.010 inch. (tenthousandths of an inch) By way of example Tin plated steel, for astainless strip S a thickness of the removable portion 820 providesadequate deformation with a thickness T (FIG. 30). For stainless steelstrip of the same thickness, a removable portion has a thickness T−0.004inch to increase the energy transmitted compared to Tin plated steelstrip. As explained below, the control 120 automatically rotates anappropriate one of the two stops 810, 812 into a die support contactingposition, depending on what strip material is passing through the punchstation. In the exemplary embodiment two stops are supported by each ofthe stop assemblies 410 but more than two stops could be used on therotatable stop body 814, so long as only one at a time of the stops ispositioned for contact with the die support.

Controlled rotation of the rotatable stop body 814 is performed bycontrolled application of fluid from a fluid source 542 (FIG. 16) to astop actuator 840 that is attached to a stop body 842 fixedly attachedto and supported by the anvil support 430. A representative stopacutator 840 is commercially available from SMC under part numberCRJB05-180 and is depicted in greater detail in the perspective view ofFIG. 19. Additional details regarding operation and performance of theactuator are available in the specification sheet for the actuator,which is incorporated herein by reference in its entirety.

As seen in FIG. 19, the actuator 840 includes a drive piston 844 havingfirst and second ends 845 (only one of which is visible in FIG. 19) thatsupports a rack gear 846 that extends along a length of the drive piston844. An actuator output shaft 848 has a pinion gear 850 at one end thatengages the rack gear 846 of the piston and a flat 852 at an oppositeend. The shaft 848 extends through a bearing 853 supported by anactuator body 860 and fits into an internal opening of the rotatablestop body 814 having a internal flat (not shown) which engages the flat850 on the shaft. A cover 854 attached to the body 860 covers thebearing 853. Rotation of the output shaft 848 due to back and forthmovement of the piston 844 causes the shaft 844 to impart back and forthrotational movement to the rotatable stop body 814. In the exemplaryembodiment, the shaft rotates a total of 180 degrees from one extreme ofpiston travel to its other extreme of travel, as indicated by arrows Rin FIG. 19.

The piston 844 is supported in the actuator body 860 having pressureconveying passageways for conveying air under pressure through thepassageways to opposed ends 845 of piston 844 for imparting back andforth movement to the piston which in turn is converted to back andforth rotation of the output shaft 848 of the stop actuator 840. As seenin FIG. 27, quick disconnect couplings 862, 864 are coupled to threadedopenings on the actuator body 860. When pressurized fluid (mostpreferably air) is transmitted from the source 542 through a valve 870to a conduit 872 (FIG. 41) coupled to the coupling 862 the piston 844moves in one sense and the rotatable body 814 rotates in acounterclockwise sense as seen in FIG. 19. When pressurized fluid (mostpreferably air) is transmitted from the source 542 through the valve 870to a conduit 874 (FIG. 41) coupled to the coupling 864, the piston 844moves in an opposite sense and the rotatable body rotates in a clockwisesense as seen in FIG. 19.

In the preferred embodiment, the control 120 monitors operation of eachof the actuators (in the preferred embodiment there are four suchactuators, two on each side of the strip). Sensors 880, 882 supported bythe body 860 are placed into a slot 884 of the body so that an end ofpiston travel indicator is sent to the controller which in turn allowsthe controller to reverse the air flow direction to the other end of thepiston that was pressured to rotate the rotatable stop body. The sensors880, 880 are commercially available from SMC, part number D-M9P-SAPC.

The rotatable stop body 814 is generally disk shaped. Extendingdownwardly from a bottom surface of the rotatable stop body is a stem886 having an outer surface that fits into a sleeve bearing 888supported within a generally cylindrical through passage 890 of the stopsupport body 842. When assembled, conforming surfaces or faces 910, 912of the rotatable stop body 814 and the stop support body 842 are incontact with each other along a generally planar interface. The stopsupport body 842 defines a fluid passageway extending from an inlet port920 on a side face of the stop support body 842 to an outlet port 922(as seen in FIGS. 32 and 40) opening that faces the conforming surfaceof the rotatable stop body. When air under pressure is forced from theoutlet port 922, a cushion of air (or air bearing) is created betweenthe rotatable stop body and the support body, thereby reducing africtional engagement between the two. This reduction in the force ofengagement allow movement of the piston 844 to re-oriente the rotatablestop body 814 and position a different stop in the path of travel of thedie support. FIG. 41 depicts a valve 930 for routing pressurized airfrom the air source through a conduit 932 to a fitting 934 attached tothe body and through the internal passageway to the outlet port 922 inresponse to a control signal from the control 120.

FIGS. 25 and 26 are a top plan view of the moveable die support 420(FIG. 25) and a bottom plan view of the moveable anvil support 430 (FIG.26). As seen in FIG. 25, the die support has a width W and the anvilsupport has a width W+Δ. In the Exemplary embodiment the width W is4.250 inches AND W+Δ is 5.750 inches. As mentioned above two stopassemblies 410 are mounted to an associated anvil support on each sideof the strip. As seen in the FIG. 25 depiction the control has rotatedtwo stops 810 having the same height out of the way of the die support.Hence, the two stops 812 that make up the stop assemblies are located inposition for limiting die movement due to impact with the die support asthat support is driven downward with its associate die.

As explained below, there is a need in flexibility in choosing theheight of the removable stops. For a typical system, during set up ofthe machine, the operator will select two sets of stops (four each) andattach them to the rotatable stop body by fitting them over the stud824, 825. Then as the strip material changes under the control of thecontrol 120, an appropriate set of two of four stops are rotated intoposition for limiting die movement on opposite sides of the strip. Tofacilitate operator set up a dimension marking is stamped onto the sidesof the removable stops. Typically, all four stops will have the sameheight dimension. If drives on the two sides of the strip were notconnected (by the drive plate 400 for example) the die movement onopposite sides of the strip may for a given punch be controlled withdifferent dimension stops.

In the exemplary embodiment the punch drives for moving the plate 400are air actuated drives. The exemplary system limits movement of thedies in a somewhat empirical fashion to achieve a best result of cornerfabrication. The correct amount of energy is determined by the use of afold force gage. A goal is to achieve the same fold force regardless ofmaterial, and make the adjustments to the stop height dimension T toachieve that goal.

An alternate example embodiment of the punch station 104 is depicted inFIG. 8. This station has two dedicated stamping stations for forming thecorners 32 a, 32 b, 32 c, 32 d. Two stamping stations 148, 148′ arecapable of stamping the three corners 32 b, 32 c, 32 d that areseparated from the tongue. And the two stamping stations 150, 150′ arecapable of stamping the corner 32 a. For one material, stainless steelfor example, the stations 148, 150 are set up for forming the corners.If a demand for tin plated steel frames is subsequently being satisfied(by the control station 120 choosing an appropriate supply roll at thestock supply station 102 for feeding through the line) the controlstation forms the corners by selective actuation of a second set ofstamping stations 148′, 150′ that deform the strip in a slightlydifferent manner.

FIG. 16 is a schematic depiction of a pneumatic system 540 forpressurizing the dual acting air cylinders 290, 292 at the punchingstation 104. The two air cylinders 290, 292 are coupled to the airsource 542 through a solenoid operated valve 544 that delivers air at 80psi to the air cylinders having a piston of ⅝ inch diameter and a throwdistance of ⅝ inch. The solenoid 544 responds to control outputs fromthe control 120 by switching back and forth from a position in which theplate 400 is raised and a position which forces the plate downwardly tonotch the strip S. Other solenoid operated valves 546 a, 546 b, 546 c,546 d are also depicted in FIG. 16. The ports for the valve 544 arelabeled in detail in FIG. 16A wherein port 1 has been labeled withreference character 548, port 2 with reference character 549, port 3labeled with reference character 551 and port 4 with reference character552.

Turning to FIG. 17, one sees the connections to the two air drivencylinders 290, 292 in more detail. A pair of T connectors route airpassing through the solenoid valve 544 to the cylinders. A first Tconnector 554 is connected to port number 2 on the solenoid valve 544.When pressurized air is provided by this port, the cylinders lift theplate 400 up against the action of gravity. When a second T connector556 receives pressured air from port number 4 of the valve 544 thecylinders drive the plate 400 downwardly in a controlled manner. Thisarrangement allows one connector (554 for example) to pressurize one ofthe internal air cylinder chambers of both air cylinders 290, 292 whileanother chamber of the cylinder is vented or exhausted through the otherconnector (556 for example) through the solenoid valve and then toatmosphere.

In the exemplary embodiment, the two air cylinders 290, 292 areconnected to an improved quick exhaust 560 (FIG. 17) available fromFesto as part number SE-1/2-B. As described in US published application2012/0011722, the quick exhaust 560 has a threaded exhaust port. A flowcontrol is threaded into the exhaust port of the quick exhaust. The flowcontrol has an integrated sintered silencer. An exemplary flow controlis available from Festo as part number GRE-1/2. A goal of use of theflow control is to not noticeably slow the speed of the dies but improvethe consistency of the strikes by the die against the strip. Statedanother way, the flow control allows for a known or regulated control ofthe exhausts to allow for a substantially repeatable load force appliedto the strip S by the dies and anvils of the punch station 104.

A study of the operation of the corner notching has led to a betterunderstanding of how various factors affect corner fold quality.Generally, after a production line is converted from Tin Plate toStainless Steel a range of fold force (forming the 90 degree anglebetween spacer frame segments 30 shown in FIG. 1) readings vary by about5 oz. That is, the force needed to bend the severed frame from itsoriginal elongated linear strip form to a closed form vary over a rangeof about 5 oz for both stainless steel and tin plated steel. It has beenfound that after an extended period of use the fold force experiencedcan often have a range of over 10 oz. This difference is attributed tochanges in the system over time such as clogged flow paths in thepneumatic circuit coupled to the cylinders 290, 292 and to structuralwear in the components forming the punch station 104, such as the guiderods 302. As the components wear, the system friction is reduced. Thisreduced friction results in inconsistent acceleration of the dies.

The die stroke is about ⅜ inch. The travel time from an up limit switchsignal to a down limit switch signal is about 7 milliseconds. Theselimit switches are attached to the air cylinder body and detect when aninner piston is up (retracted) or/down (extended) position. During this7 millesec time the acceleration and final velocity of the dies (in thedownward punch direction) is affected by several factors. Gravity isaccelerating the dies. Friction is resisting the acceleration. Airpressure coming into the cylinders is accelerating the load. Airpressure on the exhaust side of the cylinder is resisting acceleration.The shearing force required to notch the strip is trying to stop theload.

Gravity is a constant. Its force will not change over time. Friction issubstantially consistent over a relatively short time period. However,friction will change to some degree over time as wear takes place.Friction may also be sharply increased or decreased with press alignmentand die binding. Adjustments to the press can be made whichinadvertently apply a mechanical bind to the system. Air flow in and outof the cylinders will also be fairly consistent over a short timeperiod. Air flow characteristics however can change dramatically overtime. This change is experienced as mufflers or silencers becomeplugged, air flow is restricted.

When the air supply to the punch station 104 is removed, the dies willfall due to gravity. If the air supply is toggled on and off severaltimes and one observes how the dies fall, one will see some variation inthe manner in which the dies fall. Sometimes the die will fall quickly,and sometimes they may fall slower. In some cases they may only fallpart way, pause and then fall the rest of the way. Using pneumatics toconsistently accelerate a load that will freefall, leads to some smallvariations. Since air is a compressible fluid, small changes in externalconditions such as mechanical binding or air flow restrictions canresult in noticeable changes in the consistent delivery of energy to thepunch driver system. Adding the flow control after the quick exhaustachieves much greater consistency in both time and load applied to thestrip S by the dies.

Set up of the flow control is to some degree empirical but can besimplified if the actual force of engagement between the die and thestrip S is measured. This can be performed using a force gaugecommercially available from GED Integrated Solutions Inc., assignee ofthe present invention. (part number 2-24472) The Exemplary flow controlhas an adjustment feature that is adjusted by turning a screw. The flowcontrol has a tapered cone spaced from a mechanical seat. The closer thecone is to the seat, the more restricted is the airflow, on the control,the flow path through the control can be adjusted for maximum flow. Bestresults are obtained if the flow is somewhat restricted however, so thatin one exemplary system best results were obtained by rotating the screwthree turns, resulting in approximately 30% reduction in flow. Theexemplary flow controls have about 10 full turns (360 degrees) from opento closed, so 3 turns from open would be about 30% restriction. The datain Table 1 below was obtained at this setting and measures the actualmeasured force applied to a gauge in ounces for twelve readings. Notethe range from the maximum to the minimum is only 5 ounces compared tovalues measured of as much as 12 ounces for a non flow restrictedexhaust. This data is obtained by using the 2-24472 fold force gauge.

TABLE 1 Flow restricted Corner 1 Corner 2 Corner 3 48 53 48 Minimum 4848 51 48 Maximum 53 49 50 48 Range 5 48 51 49 Average 49Crimper Station 108

A crimper assembly is connected to an output end of the roll formerstation 106 and processes roll formed strip 312 output from the rollformer 210 and is described in detail in issued U.S. Pat. No. 7,448,246.

The crimper assembly includes two horizontally oriented pneumaticallyactuated cylinders having crimping fingers attached to the output driverods of these cylinders. The crimping fingers are located so that theircenter line of action extends parallel to and intersections a regionbetween the center lines of rotation of the rollers. When the cylindersare extended the crimp fingers strike the corners or leads at theircenter.

FIG. 13 is a perspective view of a crimping finger. A threaded openingin a mounting block allows the finger to attach to the output of a drivecylinder. In one example embodiment, the crimping fingers are made froma tool steel or flame hardened steel as would be appreciated by one ofordinary skill in the art.

A v-shaped contact 681 has a beveled underside 683 which extends from aconcave shaped portion 679 of the fingers 674, 676. Top portion of thecontact 681 comes into contact with the lateral walls 42, 44 of theframe structure 16 (see FIG. 1) initially and continued movement of thefingers bring the beveled underside 683 into engagement with the frameto crease the frame in the region of weakness 52 at the notch 50.

The contact 681 further comprises an apex 685 extending to the contact'smost distal point. The concave portion 679 includes two faces 701, 703,transversely located with the concave portion and spaced apart by thecontact 681. The faces 701, 703 terminate at a proximal end of thecontact 681. A cylindrical boss 707 extends from each of the faces 701and 703 beyond the apex 685 of the contact 681. The cylindrical bosses707 are received and supported by a cylindrical support opening 709located hi respective faces 701, 703 and extend beneath the concaveportion 679 of the fingers 674, 676.

Securing the bosses 707 into the respective support openings 709 arerespective fasteners 711. In one example embodiment, the fasteners 711are socket head set screws. In another example embodiment, thecylindrical bosses 707 are supports sold by GED Integrated Solutionsunder part number 758-0220.

During operation, an apex 685 of the fingers centrally engages (alongthe z axis of FIG. 21) the area of weakness 52 by the apex 685, whichcontinues to a prescribed first depth along the x axis of both lateralwalls 42, 44 of the frame 16. Once the first prescribed depth isreached, the cylindrical bosses 707 contact symmetrically at first andsecond points 713, 715 about the area of weakness the lateral walls 42,44. This removes contact between the lateral walls and apex 685, whilecontinuing the deformation of the respective lateral wall near theregion of weakness 52 along the x axis to a second depth. Both the firstand second prescribed depths occur in a single advancement of bothfingers during a single cycle. In one example embodiment, the differencebetween the first prescribed depth and the second prescribed depth is0.030 inches.

While an exemplary embodiment of the invention has been described withparticularity, it is the intent that the invention include allmodifications from the exemplary embodiment falling within the spirit orscope of the appended claims.

The invention claimed is:
 1. Apparatus for fabricating spacer framesfrom strip stock of different material for use in an insulating glassunit, said apparatus including multiple work stations for treating anelongated strip of said strip stock as the elongated strip moves throughsuccessive work stations comprising: a) a punching station having apunch drive that moves a die into engagement with a flat surface of theelongated strip at controlled locations along a length of said elongatedstrip to form corner locations that facilitate bending of the elongatedstrip into a closed multi-sided structure, wherein the punching stationhas an adjustable stop with multiple stop surfaces that can be rotatedinto an engagement position that limits movement of the die into theelongated strip to a controlled amount; b) a forming station that formsa spacer frame from the elongated strip having side walls to which anadhesive is applied during fabrication of an insulated glass unit; c) asevering station that separates a lead spacer frame from subsequentspacer frames after the lead frame has moved through the punching andforming stations; and d) a control station that adjusts energytransferred during engagement between the die and the elongated strip atthe punching station by rotating a selected one of the multiple stopsurfaces into the engagement position.
 2. The apparatus of claim 1wherein the adjustable stop includes a stop body and a stop body supportmounted in relation to a path of travel of the elongated strip whereinthe stop body defines first and second different movement limiting stopsurfaces located on different regions of the stop body wherein theadjustable stop further comprises and further comprising a fluid sourceand a stop actuator responsive to the fluid source rotates the stop bodyrelative to the stop body support to position a selected limiting stopsurface in the engagement position which limits movement of the dieduring a punch stroke of the die.
 3. The apparatus of claim 2 whereinthe die is supported by a die support having a generally planar contactsurface which moves in response to controlled actuation of the punch bythe control station and wherein the die support contact surface engagesa movement limiting surface of the selected limiting stop surfacepositioned in the engagement position.
 4. The apparatus of claim 2wherein the stop actuator comprises a drive piston having first andsecond ends having a drive gear extending along a length of the drivepiston, and an output shaft coupled to the stop body for rotating thestop body and including a driven gear that engages the drive gear ofsaid piston to impart rotational movement to the output shaft inresponse to movement of said piston.
 5. The apparatus of claim 4 whereinthe actuator has an actuator body having pressure conveying passagewaysfor conveying air under pressure through the passageways to opposed endsof piston for imparting back and forth movement to the piston which inturn is converted to back and forth rotation of the output shaft of thestop actuator.
 6. The apparatus of claim 5 wherein the stop body isgenerally disk shaped and wherein conforming surfaces of the stop bodyand the stop body support are generally planar, further wherein the stopbody support comprises a passageway leading to a port facing theconforming surface of the stop body for reducing a force of engagementbetween the stop body and the stop body support to allow rotation of thestop surfaces of the stop body.
 7. The apparatus of claim 2 wherein thestop body comprises a plurality of magnets and a positioning post foreach of a number of different dimension removable stops that fit over arespective positioning post and are held in place by the magnets.
 8. Theapparatus of claim 1 wherein the punching station comprises first andsecond dies mounted to die supports on opposite sides of the elongatedstrip that forms corner locations on opposed regions of the elongatedstrip and further wherein the punching station comprises adjustablestops on each side of the elongated strip for limiting movement of eachof said dies.
 9. Apparatus for fabricating elongated spacer frames fromstrip stock including multiple work stations for treating strip stock asan elongated strip of the strip stock moves through the multiple workstations comprising: a) punching station having a punch drive that movesa die into contact with a flat surface of the strip stock at controlledcorner locations along a length of said elongated strip and anadjustable stop that can be rotated into an engagement position thatlimits movement of the punch drive to control engagement between theelongated strip and the die; said adjustable stop comprising a stop bodyhaving first and second stop body contact regions, a stop body support,a source of compressed air that routes air into a region between thestop body and the stop body support to lessen a force of engagementbetween the stop body and the body; b) a forming station that bends thestrip into a desired shape; c) a severing station that separates a leadspacer frame from subsequent spacer frames after the lead spacer framehas moved through the punching and forming stations; and d) an actuatorthat moves the stop body relative to the stop body support to position aselected one of the stop body contact regions into an engagementposition to limit movement of said die.
 10. The apparatus of claim 9wherein the punching station comprises: a) a first die assemblysupporting a first die that deforms one side of the elongated strip; b)a second die assembly supporting a second die that deforms an oppositeside of the elongated strip; c) a ram assembly including the punch drivecoupled to the first and second die assemblies that drives the first andsecond dies into engagement with the elongated strip; and d) whereinsaid adjustable stop limits movement of the ram assembly.
 11. Theapparatus of claim 10 wherein the punching station comprises first andsecond anvils defining a slot which accommodates movement of theelongated strip through the punching station and further comprising asharp edged ridge on the first and second dies which help deform theelongated strip when the elongated strip is impacted between the die andthe anvil.
 12. The apparatus of claim 11 comprising first and secondadjustable stops on opposite sides of the strip path of travel which arecontacted by the ram assembly to control deformation of the elongatedstrip by the first and second die assemblies.
 13. The apparatus of claim10 wherein the punch drive comprises an air actuated drive and whereinthe pressure supplied to the air actuated drive is adjusted to controldeformation of said elongated strip by the punching station. 14.Apparatus for fabricating spacer frames for use in an insulating glassunit, said apparatus including multiple work stations for treating anelongated strip as the elongated metal strip moves through successivework stations along a strip path of travel comprising: a) a punchingstation comprising: i) a punch drive that moves a die into engagementwith a flat surface of the metal strip at controlled locations along alength of metal elongated strip to form corner locations that facilitatebending of the elongated strip into a closed multi-sided structure; andii) an adjustable stop comprising a stop body and stop body supportmounted in relation to the strip path of travel wherein the stop bodydefines first and second different movement limiting stop surfaceslocated on different regions of the stop body that can be rotated intoan engagement position that limits movement of the die to a controlledamount that depends on a type of material of the elongated strip passingthrough the punching station; b) a roll forming station that bends theelongated strip to form spacer frame side walls to which an adhesive isapplied during fabrication of an insulated glass unit; c) a severingstation that separates a lead spacer frame from subsequent spacer framesafter the lead spacer frame has moved through the punching and rollforming stations; and d) a control station that adjusts energytransferred during engagement between the die and the elongated strip atthe punching station comprising a stop actuator that rotates a selectedone of the movement limiting stop surfaces into the engagement position.15. The apparatus of claim 14 further comprising a fluid source andwherein the stop actuator is responsive to the fluid source that rotatesthe stop body relative to the stop body support to position a selectedone of the limiting stop surfaces in an engagement position limitsmovement of the die during a punch stroke of the punch drive.
 16. Theapparatus of claim 15 wherein the die is supported by a die supporthaving a generally planar contact surface which moves in response tocontrolled actuation of the punch drive by the control station andwherein the die support contact surface engages one of the movementlimiting stop surfaces of the adjustable stop positioned in theengagement position.
 17. The apparatus of claim 15 wherein the stopactuator comprises a drive piston having first and second ends having adrive gear extending along a length of the drive piston, and an outputshaft coupled to the stop support for rotating the stop support andincluding a driven gear that engages the drive gear of said piston toimpart rotational movement to the output shaft in response to movementof said piston.
 18. The apparatus of claim 17 wherein the stop actuatorhas an actuator body having pressure conveying passageways for conveyingair under pressure through the passageways to opposed ends of the drivepiston for imparting back and forth movement to the drive piston whichin turn is converted to back and forth rotation of the output shaft ofthe stop actuator.
 19. The apparatus of claim 18 wherein the stop bodyis generally disk shaped and includes a generally planar surface facinga conforming surface of the stop body support, further wherein the stopbody support comprises a passageway leading to a port facing thegenerally planar surface of the stop body for reducing a force ofengagement between the stop body and the stop body support to allowreorientation of the stop surfaces of the stop body.
 20. The apparatusof claim 14 wherein the stop body comprises a plurality of magnets andone or more positioning posts for mounting different dimension removablestop bodies having recesses that fit over a respective positioning postand are held in place by the magnets.
 21. The apparatus of claim 16wherein the punching station comprises first and second dies mounted todie supports on opposite sides of the strip for forming corner locationson opposed regions of the strip and wherein first and second stop bodiesare mounted to the stop body supports on each side of the strip forlimiting movement of said first and second dies.
 22. The Apparatus ofclaim 16 comprising: a source of compressed air for routing air into aregion between the stop body and the stop body support to lessen a forceof engagement between the stop body and the body.
 23. The apparatus ofclaim 22 wherein the punching station comprises: a) a first die assemblysupporting a first die for deforming one side of the strip; b) a seconddie assembly supporting a second die for deforming an opposite side ofthe elongated strip; c) a ram assembly including the punch drive coupledto the first and second die assemblies for driving the first and seconddies into engagement with the elongated strip; and d) first and secondadjustable stops for limiting movement of the first and second dies. 24.The apparatus of claim 23 wherein the punching station comprises firstand second anvils defining a slot which accommodates movement of theelongated strip through the punching station and further comprising asharp edged ridge on the first and second dies which help deform theelongated strip when the elongated strip is impacted between the die andthe anvil.
 25. The apparatus of claim 24 wherein the first and secondadjustable stops are contacted by the ram assembly to controldeformation of the strip by the first and second die assemblies.
 26. Theapparatus of claim 23 wherein the punch drive comprises an air actuateddrive and wherein the pressure supplied to the air actuated drive isadjusted by said control station.